1. Field of the Invention
The present invention relates generally to a pump apparatus powered by compressed air and used to fill or evacuate containers such as fifty-five gallon drums, and more particularly to a pump apparatus with a fluid amplifier that creates a vacuum inside the container to fill the container or pressurizes the container to evacuate it.
2. Description of Related Art
A variety of known apparatus can fill containers such as fifty-five gallon and thirty gallon drums with liquid and discharge liquid from such containers. These devices either create a vacuum inside the container to facilitate the filling of the container, or they pressurize the container to facilitate evacuation. Some of these devices, known as xe2x80x9cdrum pumpsxe2x80x9d have a large number of industrial applications, including the transport of metal cutting fluids, paints, non-flammable solvents, and similar materials in and out of fifty-five gallon drums.
The prior drum pumps typically include an air flow amplifier assembly such as the one described in U.S. Pat. No. 4,046,492. This assembly when used in a xe2x80x9cdrum pumpxe2x80x9d type application receives compressed air and creates a vacuum in a drum during a filling mode of operation. It also pressurizes the container during a discharging mode of operation. In the fill mode of operation, a suction end of the amplifier, which extends into the drum, pulls air out of the drum and liquids into the drum through a conveying hose. A float valve assembly lies connected to the suction end of the amplifier. Rising fluid raises a float in the float valve assembly which stops the vacuum flow between the pump and the drum, preventing over-filling of the drum.
In the discharge mode, a plug assembly of this prior pump assembly closes the air flow amplifier, forcing the compressed air to flow directly into the drum. The compressed air then pressurizes the drum and forces the liquid in the drum out through the conveying hose. A pressure relief valve prevents over-pressurization of the container and any damage to the drum by allowing the compressed air to discharge from the drum.
One specific example of a prior drum pump apparatus 20, shown in FIGS. 8-12, includes a body 21 with an air flow amplifier 22, a compressed air inlet 23, a float valve assembly 24, and a plug assembly 25 having a pressure relief valve 26 and a handle 27. The handle 27 lies threadably mounted to the body 21 and allows an operator to thread it between a position in which the plug assembly closes the air flow amplifier and a position in which the plug assembly leaves the air flow amplifier open.
The pump apparatus shown in FIGS. 8-12 suffers a number of disadvantages. First, when installed on a drum or other container, it does not allow easy adjustment of the position of the compressed air inlet. When moving it from drum to drum, it requires disconnecting it from the compressed air conduit or hose. In addition, the adjustment of the plug handle between the fill and discharge modes requires multiple rotations of the handle. It does not allow quick and easy placement of the plug. Also, this pump apparatus, when placed in the fill mode, discharges compressed air at a substantial distance from the top of the drum with which it cooperates; resulting in splashing of any liquid that collects on top of the drum. Finally, the construction of this prior pump apparatus requires expensive and precisely manufactured components and complex and costly fabrication procedures.
The pump apparatus of the present invention avoids the disadvantages of the prior art pumps. It has a simple construction which minimizes the expense of manufacture and assembly. It allows easy adjustment of the position of the compressed air inlet after installation on a corresponding drum. It allows fast and easy adjustment of the plug to initiate the fill and discharge modes. And, it discharges compressed air proximate the top of the drum to minimize splashing and spilling.
In accordance with one embodiment of the present invention, a pump apparatus includes a body member, which defines an air flow passageway for receiving compressed air and for amplifying its volume (flow), and a compressed air inlet which communicates with the passageway. The body member includes a main segment and an insert segment that extends into a container. The insert segment rotates relative to the main segment.
A cover member lies over the body member, a spaced distance outwardly of the body member. A plug assembly lies mounted on the cover member proximate the body member. The plug assembly closes and opens one end of the passageway in the body member. It includes a plunger disposed in sliding engagement with the cover member. This plunger has a gripping portion at one end and a valve assembly at an opposite end. The plunger defines a groove which cooperates with a protrusion in the cover member to guide the plunger along a substantially linear path.
The cover member lies releasably secured to the body member by at least one securing member. The securing member extends through the main segment of the body member and into a groove in the insert segment to pivotally connect the main segment to the insert segment. The pump apparatus of the present invention may include more than one securing member, e.g., three shoulder screws.